1. Field of the Invention
The present invention relates to an apparatus for the recovery and reuse of exhaust gases in manufacturing processes using special material gases, and relates to a vacuum exhausting apparatus and method for conducting manufacturing processes in ultraclean atmospheres.
2. Background Art
In various processes which employ special material gases, a problem arises in that, among the exhaust gas components, exhaust gas components such as radicals or the like which remain unreacted or incompletely reacted are deposited on the surfaces of the exhaust line, and presently, regular maintenance is required.
Among the methods conventionally employed in exhaust gas processing apparatuses, removal apparatuses exist which employ dry methods, wet methods, and combustion methods.
In combustion type removal apparatuses, removal is conducted by the combustion of combustible gases, and after this, water is applied and soluble materials dissolve. In the wet removal apparatuses, gases which are soluble in water are removed. However, in these two methods, it is also necessary to treat the solution, and furthermore, once combustion has occurred, it is impossible to reuse the resources.
In dry removal apparatuses, using an adsorbing material, harmful gases are adsorbed and removed. In this case, as well, it is necessary to process the adsorbing material.
Furthermore, it is not merely the case that recovery methods have not been established; there is also a problem in that, even in vacuum exhaust methods, the exhaust gases diffuse back within the pump, and return again to the processing spaces.
The present invention has as an object thereof the cooling, liquefaction, recovery and reuse of exhaust gas components in manufacturing processes, and to make it possible to use toxic or useful gases without the necessity of disposal. Furthermore, the present invention has as object thereof to drastically reduce the frequency of the maintenance of exhaust systems by combining this recovery method with a vacuum exhaust system.
As a result of diligent research, the present inventors have discovered that by subjecting the exhaust gas components which are unreacted or incompletely reacted, and are a cause of deposition, to adsorption, breakdown, or gasification, the occurrence of deposition is suppressed, and furthermore, by cooling the gases, liquefaction takes place, and in the liquid state, the recovery of harmful or useful gases can be conducted. In other words, the present invention is characterized in that, in a gas recovering apparatus comprising followings disposed downstream from the chamber in an exhaust line, adsorption columns for adsorbing one or more exhaust gas components within a exhaust gas from a chamber, or reaction tubes for directly degrading such components, a means for introducing gas which is able to react to said exhaust gas components upstream from said adsorption tubes or reaction tubes, and cooling tubes for liquefying and recovering exhaust gases from said adsorption tubes or reaction tubes.
Furthermore, the present inventors have discovered that the reverse dispersion of the exhaust gases can be suppressed by causing the flow of an appropriate amount of gas from appropriate positions in the exhaust line. In other words, the present invention comprises a vacuum exhaust method comprising a mechanism for introducing gas, a vacuum exhaust apparatus for exhausting gas and a chamber for storing a vacuum, wherein the interior of the chamber is constantly subjected to the flow of some type of gas; the present invention also comprises a vacuum exhaust apparatus in which the mechanism for introducing gas is provided between the vacuum exhaust pump and the chamber.
By means of the gas recovery apparatus of the present invention, exhausted gases which were conventionally disposed of can be recycled and reused.
Furthermore, by means of the vacuum exhausting method and apparatus of the present invention, it is possible to suppress the reverse diffusion of the exhaust gas components within the pump.